Ice cores provide information about past climate and environmental conditions on timescales from decades to hundreds of millennia, and direct records of the composition of the atmosphere. As such, they are cornerstones of global change research. For example, ice cores play a central role in showing how closely climate and greenhouse gas concentrations were linked in the past, and in demonstrating that very abrupt climate switches can occur.

With the completion of major projects in Greenland and Antarctica over the last 15 years, the international ice coring community is planning for the next several decades. The costs and scope of future work create the need for coordinated international collaboration. Developing this international collaboration is the charge of IPICS, the International Partnerships in Ice Core Sciences, a planning group currently composed of ice core scientists, engineers, and drillers from 18 nations. IPICS is supported by PAGES (Past Global Changes), SCAR (Scientific Committee on Antarctic Research) and IACS (International Association of Cryospheric Sciences), although it is not a formal project under any of these organizations.

Two international meetings in 2004 and 2005 (Brook, E. and Wolff, E.W., The future of ice core science, EOS, 87 (4), p. 39. 2006) lead to an ambitious four-element framework that both extends the ice core record in time and enhances spatial resolution. The scientific goals and their implementation have been outlined in the four IPICS White Papers - available from the IPICS website.

1. Searching for the longest possible ice core record. The oldest Antarctic ice core so far extends 800-900 kyr. Before this, Earth's climate had a 40 kyr glacial-interglacial periodicity. IPICS aims to find a 1.2 Myr record and help discover why the period changed. During IPY, initial survey work will occur as part of the TASTE-IDEA ice divides traverses, by French/Italian/Russian teams in the Dome C-North Vostok-Dome B region, by a Chinese team near Dome A, and by US-led radar and remote sensing teams. IPICS will collate results to recommend drilling sites.

2. Initiation of coring to recover the last interglacial and older ice from Greenland. The last interglacial was probably warmer than the present and is an analogue for an anthropogenically-warmed world. We need to learn about the behaviour of climate and the Greenland ice sheet during times of warmer climate. The oldest reliable core only partly penetrates the last interglacial. Drilling in northwest Greenland would start, and possibly finish, in IPY. Danish, US, French, Japanese, UK, Swiss, Swedish, and German groups have expressed interest, and others are expected to join. Note that while this effort is part of the IPICS agenda, it also falls under IPY lead project # 561 (Greenland's Ice Sheet - reactions to past and present climate change), which will lead IPY efforts related to this element of IPICS.

3. Starting a detailed spatial network of deep and intermediate-depth Antarctic ice cores. The spatial pattern of change is key to climate dynamics. We have cores from central East Antarctica and from a few coastal regions, but additional data are needed from other key areas, including the northern part of Lake Vostok, coastal Antarctica, the Antarctic peninsula, and West Antarctica. New projects like the European drilling at Talos Dome (east Antarctica) will take place during IPY. These programs will provide a springboard for a larger effort to fully sample Antarctic spatial climate variability on all possible time scales.

5. The WAIS Divide Ice Core. This West Antarctic ice core will produce the best climate record covering the past 100,000 years, including highly resolved histories of atmospheric carbon dioxide and other greenhouse gases, and millennial and shorter time-scale climate change in Antarctica. The main drilling starts during IPY, in the 2007/2008 Antarctic field season.

4. Late Holocene climate change. Future change can only be assessed in the context of natural climate variability. Highly resolved compilations of past global climate (timescale up to 2000 years) critically lack polar data. The SCAR project, ITASE, produced 250 cores that cover the last 250 years. Extending this time scale to the last millennium, and expanding the scope in the Arctic, are critical. IPY will engage all countries to complete work in Antarctica and continue the effort in the Arctic.

6. SOFIA (Search for the Oldest Firn Interstitial Air). SOFIA aims to obtain firn air records spanning more than the last 150 years, encompassing much of the period from the industrial revolution to the present day. Large firn air samples are critical for understanding this period of atmospheric history as they allow measurements (of trace species or isotopic ratios) that are otherwise impossible with ice core samples.